Apparatus for regulating or controlling the pressure of the current in an electric circuit.



J. WATKINSON & A. E. PAYNE. I APPARATUS FOR REGULATING 0R CONTROLLING THE PRESSURE OF THE CURRENT IN AN ELECTRIC CIRCUIT.

APPLICATION FILED JUNE 13, 1910.

983,414. Patented Feb. 7, 19 1.

UNITED srnrns r nrnnr OFFICE.

JACOB WATKINSON AND ALBERT E. PAYNE, OF LONDON, ENGLAND.

APPARATUS FOR REGULATING OR CONTROLLING THE PRESSURE OF THE CURRENT IN AN ELECTRIC CIRCUIT.

Application filed June 13, 1910.

To all whom it may concern.

Be it known that we, JACOB TVATKINSON and ALBERT EDWARD PAYNE, residing at 138 Cambus road, Canning Town, London, England, have invented certain new and useful Improvements in Apparatus for Regulating or Controlling the Pressure of the Current in an Electric Circuit; and we do hereby declare the following to be a full, clear, and exact description or the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an improved apparatus for regulating or controlling the pressure of the current in an electric circuit, of the kind wherein a switch arm is adapted to be moved over a series of contacts connected to a group of resistance devices each consisting of cells, or groups or blocks of graphite or other material. In apparatus of this kind hitherto made it has been proposed to employ a switch arm having members which were pressed on to the contacts by spiral springs but it is found in practice that such devices are unsatisfactory and are liable to burn out with high pressures.

The object of the present invention is to provide improved means for obtaining an cllicient ant safe contact between the movable and fixed parts, and also to provide an apparatus of generally improved construction.

The invention consists in the combination with a series of resistances composed of separate pieces of graphite or similar material clamped together in groups and suitably connected to contacts, of a pivoted switch arm carrying a roller or rollers or blocks mounted on resilient arms, which rollers or blocks are adapted to bear upon the contacts, the said switch arm being also provided with fiat spring arms to further insure an eflicient contact.

The accompanying drawings illustrate two forms of the improved apparatus made in accordance with the invention.

Figure 1 is a part sectional plan of one form of the improved apparatus with the cover removed. Fig. 2 is an elevation. Fig. 3 is a plan with the cover removed, of a modification, and. Fig. i is an elevation of Fig. 3.

As shown, this device comprises essentially a series of resistances electrically connccted as hereinafter described to a switch Specification of Letters Patent.

' circuit.

Patented Feb. '7, 1911.

Serial No. 586,579.

comprising a series of contact plates or strips 1, f2, 3-, l, 5, 6, 7, 7 and 7 insulated one from the other and packed within a suitablecasing 64 and rigidly secured by an adjusting screw or screws a A common contact plate 6 is provided connected to one of the main circuit wires as shown and contact is made as desired between any one of the plates or strips a and the common contact plate 6 by means of rollers c c mounted on spring arms (Z (Z carried upon the pivoted switch arm 6 provided with an ordinary operating handle or knob The switch arm 0 also carries fiat spring members f adapted to bear upon the contact a and o to insure an eflicient contact. The rollers 0 care made of sutliciently large diameter to prevent the contact being broken when the switch arm is moved from one contact strip to another.

A, B, C, D, E, F, are resistances each composed of a series of blocks or pieces of graphite or other material of circular section, disposed in cells or recesses in a common plate or frame 9, and insulated as at 9 The resistances B and C at one end are not insulated and are thus coupled together by part 9 of the frame and the resistances l) and lit, and E and F, are connected to gether as at g and 5 respectively. The wire 9 is coupled to the binding posts 21 and 22 at the left hand ends of the resistances D and E. Plate 5 is coupled to post 22, and plate 6 is coupled to wire 9 which connects the right hand ends of resistances E and F. Plate 7 is coupled. to post 23.

In "operation, assuming that the switch arm is in position so as to complete the circuit through the contacts Z) and 1, the current will pass direct to the lamp or other main by the binding-post and the connection ]L. If new contact is made with the part 2 the resistance A is brought into circuit through connections a and and bind ing screws 7; and Z, the circuit being from plate 2, through wire a, binding-post 7:, resistance A, binding-post Z, wire j, bindingpost 20, to wire /2 Upon again moving the switch arm on to contact 3, resistances A and B are in circuit, and so on, until the last contact 7 causes all resistances to be in The strip 7" is disposed intermediate of the oil contact 7" so as to insure the switch arm resting either on the last contact 7 or completely oil. The strip 7- is adjustable longitudinally the same as the other strips, but the contact-plate 7" is not adjustable. The strip 7 prevents an imperfect contact from being made through the strip 7, which might occur if the roller 0 could bear on strip 7 and plate 7* simultaneously, and pass direct from one to the other, Without passing over a neutral strip 7:

Figs. 3 and 4E show a modified construction wherein only four resistances are employed, G, H, I, K. In this form the switch arm 6 is disposed horizontally upon a bridge piece Z2 forming the common contact above the resistance frame 9 so as to economize space, and the arm 0 is provided with a flat spring arm (Z carrying a roller 0 as before. In this form the graphite blocks forming the resistances are of flat section with curved or beveled sides to prevent undue heating. 1, 2, :3, at are the contacts disposed directly upon the frame g and 4 is the off contact. In the form shown the switch is shown at the off poj sition.

In use when the roller 0 is upon the con 1 tact 1, the circuit is completed without passing through any of the resistances. Upon moving the roller 0 to the contact 2 the current passes through resistance Gr. lVheni the roller rests on the plates 2 and 3 the current passes through resistances G and H, through theframe g f] to plate 1. \Vhen the roller rests on contact-plate 4 the current passes from the roller 0, through resistance I, wire m, resistance K, wire m resistance H frame g, to plate 1.

'hat we claim is:

The combination, with a series of resistances each provided with a separate contactplate, of a pivoted switch arm constantly included in the circuit, a spring secured to the said arm at one end, a revoluble roller carried by the free end portion of the said spring and adapted to roll over the ends of the contact-plates and to include the said resistances in the circuit one after another as set forth, and a second spring also secured to the said arm at one end and having its free end portion arranged to bear on the ends of the (TOHl'ilCt-Plflt'O adjacent to the said roller.

In testimony whereof we aflix our signatures, m presence of two witnesses.

J. IVATKINSON. A. E. PAY NE.

lVitnesses C. ERIC CLoUon, Srnxnr R. Tin-Lon. 

